The primary objective of the proposed research is to determine if the red cells from the newborn infant behave differently than the red cells of normal adults under conditions of reduced oxygen tension that simulate the intrauterine environment. Parameters to be measured include red cell glycolysis, red cell deformability and response to oxidant compounds. BIBLIOGRAPHIC REFERENCES: Oski, F.A. and Komazawa, M. Metabolism of the erythrocytes of the newborn infant. Sem. in Hemat., 12: 209, 1975. Komazaws, M., Landaw, S.A. and Oski, F.A.: Lack of relationship of red cell enzyme activity to bilirubin and carboxyhemoglobin levels in healthy term infants. Acta Paed. Scand., 64: 473, 1975.